Classifications

• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K3/00—Apparatus or processes for manufacturing printed circuits
  • H05K3/40—Forming printed elements for providing electric connections to or between printed circuits
  • H05K3/403—Edge contacts; Windows or holes in the substrate having plural connections on the walls thereof
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K3/00—Apparatus or processes for manufacturing printed circuits
  • H05K3/40—Forming printed elements for providing electric connections to or between printed circuits
  • H05K3/4038—Through-connections; Vertical interconnect access [VIA] connections
  • H05K3/4053—Through-connections; Vertical interconnect access [VIA] connections by thick-film techniques
  • H05K3/4069—Through-connections; Vertical interconnect access [VIA] connections by thick-film techniques for via connections in organic insulating substrates
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K1/00—Printed circuits
  • H05K1/02—Details
  • H05K1/0296—Conductive pattern lay-out details not covered by sub groups H05K1/02 - H05K1/0295
  • H05K1/0298—Multilayer circuits
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K1/00—Printed circuits
  • H05K1/02—Details
  • H05K1/03—Use of materials for the substrate
  • H05K1/0393—Flexible materials
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K1/00—Printed circuits
  • H05K1/02—Details
  • H05K1/09—Use of materials for the conductive, e.g. metallic pattern
  • H05K1/092—Dispersed materials, e.g. conductive pastes or inks
  • H05K1/095—Dispersed materials, e.g. conductive pastes or inks for polymer thick films, i.e. having a permanent organic polymeric binder
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
  • H05K2201/09—Shape and layout
  • H05K2201/09209—Shape and layout details of conductors
  • H05K2201/095—Conductive through-holes or vias
  • H05K2201/09645—Patterning on via walls; Plural lands around one hole
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
  • H05K2201/09—Shape and layout
  • H05K2201/09818—Shape or layout details not covered by a single group of H05K2201/09009 - H05K2201/09809
  • H05K2201/09845—Stepped hole, via, edge, bump or conductor
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
  • H05K2201/09—Shape and layout
  • H05K2201/09818—Shape or layout details not covered by a single group of H05K2201/09009 - H05K2201/09809
  • H05K2201/09854—Hole or via having special cross-section, e.g. elliptical
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K2201/00—Indexing scheme relating to printed circuits covered by H05K1/00
  • H05K2201/09—Shape and layout
  • H05K2201/09818—Shape or layout details not covered by a single group of H05K2201/09009 - H05K2201/09809
  • H05K2201/09981—Metallised walls
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K3/00—Apparatus or processes for manufacturing printed circuits
  • H05K3/10—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern
  • H05K3/12—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using thick film techniques, e.g. printing techniques to apply the conductive material or similar techniques for applying conductive paste or ink patterns
  • H05K3/1216—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern using thick film techniques, e.g. printing techniques to apply the conductive material or similar techniques for applying conductive paste or ink patterns by screen printing or stencil printing

Definitions

• the invention relates to printed electrical circuits comprising a dielectric support, in particular a sheet or film of flexible plastic, on both sides of which electrically conductive networks are formed.
• a dielectric support in particular a sheet or film of flexible plastic
• connection means When the support is a rigid dié ⁇ electric plate or resin epoxy for example glass, is usually drilled holes at desired locations in the support and a film is formed graphic- * conductor on the walls of these holes by electroplating, which is a long and costly operation, greatly increasing the cost price of the printed circuit.
• the support is a flexible plastic sheet or film
• an electrically conductive elastomer which is then vulcanized or polymerized by heating and which provides an electrical connection between the tracks of the two networks passing at the ends of the hole.
• the vulcanization or polymerization of the elastomer is accompanied by a shrinkage phenomenon, causing cracks and micro-cracks at the ends of the hole, hence the risk of breaking the electrical connections, which get worse when the flexible circuit is
• the object of the invention is to provide a printed electrical circuit, in particular of the type comprising a flexible support such as a film of dielectric plastic material, in which the problems of connection between the electrically conductive networks formed on the two faces of the support are solved by simple, economical and particularly reliable.
• the invention provides a printed circuit comprising a dielectric support, in particular a sheet of flexible plastic material, and electrically conductive networks formed on the two faces of the support and interconnected by connecting means, at least some of which are made up by a hole in the support through which pass at least two different connections formed by thin strips of electrically conductive material extending at a distance from each other on the wall (s) of the hole in the support, characterized in that said strips are formed by deposition or printing by screen printing of an electroconductive ink on the wall or walls of the hole of the support.
• a hole in the support makes it easy to establish several different connections between different tracks of the two printed networks formed on the two faces of the support;
• connections are thin strips of conductive material formed by screen printing on one part of the wall of the support hole, these thin strips being, due to their small thickness, free from the risks of cracks or micro-cracks which would occur if a large thickness of material were used to establish the connections between the two networks.
• these connections are formed, along the walls of the holes of the support at the same time as the: ' networks printed on the two faces of the support, which reduces the number of manufacturing operations and avoids resumption of printed circuits after formation of electroconductive networks.
• the invention also relates to a multi-layer printed circuit comprising a printed circuit of the type described above, at least one of the faces of which is covered with a second dielectric support, such as a sheet or a film of flexible plastic material. , the outer face of which has an electrically conductive network, connected to at least one of the networks printed on the first support by at least one hole in the second support through which pass one or more electrical connections formed by depositing or printing by screen printing ink strips conductive on part of the wall (s) of the hole.
• a second dielectric support such as a sheet or a film of flexible plastic material.
• a printed circuit comprising a flexible support of dielectric material, provided with electrically conductive networks on its two faces and connections between the two networks passing through holes in the support, then to fix , for example by bonding, a film of dielectric plastic on one face of this printed circuit, this film comprising connection holes at the desired locations, and to form by printing by serial printing a conductive network on the external face of this film flexible, the connections between this network and the network or networks of the first circuit being established by the holes in the film with which one or more parts of the walls are provided a thin layer of electroconductive ink.
• FIG. 1 is a partial schematic perspective view of a printed circuit according to the invention?
• FIG. 2 is a schematic sectional view of a multi-layer printed circuit according to the invention.
• the printed circuit board shown in Figure 1 comprises a dielectric support 10, for example a polyester film having a thickness of about 0.1 mm, the upper face 11 is provided with the electrically conductive network comprising tracks ment notam ⁇ 12 and whose lower face 13 also has a conductive network comprising tracks 14.
• the connections between these two conductive networks that is to say between the various tracks 12 of the first network and the tracks 14 of the second network, are established 1 by the through holes 15 of the support, which may be square or rectangular as shown in the drawing, a polygonal shape, • circular, oval, etc.
• the hole 15 is of square section and has four plane faces 16 of two to two perpendicular, the height of which is equal to the thickness of the film 10 of plastic.
• the conductive tracks 12, 14 of the electroconductive networks arrive at the edges of the flat faces 16 of the hole 15, as shown in the drawing.
• Each track 12 of the conductive network formed on the upper face 11 of the support 10, leading to a flat face 16 of the hole 15 ,. is connected to a track 14 of the conductive network formed on the underside 13 of the support, by a strip 17 of electroconductive material, arranged on a part of. said flat face 16 and joining the end of track 12 to the end of track 14.
• the conductive networks comprising the tracks 12 and 14 are formed on the support 10 by deposition by screen printing of an electroconductive ink of a type available on the market.
• the conductive networks of the two faces of the support 10 can be printed at the same time, or else one after the other, according to the various methods of printing by screen printing.
• the connection strips 17 are formed at the same time as the electrically conductive networks, this operation presenting no difficulty.
• the support 10 is then subjected to heating, for example at a temperature of the order of 150 ° C. for a period of 5 to 10 minutes depending on the ink used, to polymerize the ink and harden it.
• connection strips 17 formed on the walls 16 of the hole 15 thus have the same nature and the same thickness as the tracks 12 and 14 of the electrically conductive networks formed on the: two faces of the support 10 and undergo polymerization heating at the same time as these networks.
• Such a treatment makes it possible to avoid all the risks of withdrawal of the electroconductive ink during its polymerization, hence a total absence of cracks and micro-cracks at the ends of the strips 17.
• the connections thus obtained are particu ⁇ completely homogeneous and free from defects.
• FIG. 2 diagrammatically represents, in section, a printed circuit with multi-ply layers according to the invention.
• This circuit 20 comprises for example a first circuit 21, of the type described in FIG. 1, comprising a dielectric support 22 formed for example from a plastic film flexible, the two faces of which have an electroconductive network comprising tracks 23 and 24 respectively, interconnected via holes 25 of * . support 22, the walls of which have connection strips 26 similar to the connection strips 17 in FIG. 1.
• a dielectric support 28 for example a flexible plastic film identical to the film constituting the support 22 of the first circuit, which is provided with holes 29 at the appropriate locations.
• This film 28 is fixed for example by gluing to the upper face of the circuit 21.
• the film 28 has on its upper face an electrically conductive network comprising tracks 30 connected to tracks 23 and / or tracks 24 of the first circuit by connection strips 31, identical to the connection strips 17, formed on part of the holes 29 of the support 28.
• the tracks 30 and the connection strips 31 can be formed by deposition by screen printing of an electroconductive ink and polymerization of this ink, after the film 28 has been fixed to the printed circuit 21.
• the assembly thus obtained can be further coated with a film 32 of dielectric flexible material, similar to films 28 and 22, having connection holes 33 at desired locations, and an electroconductive network comprising tracks 34 on its upper face and connection strips 35 formed on a part of the walls of the holes 33, in the same way as above.
• a track 34 of the upper face of the film 32 can be connected to a track 30 of the upper face of the film 28, to a track 23 of the upper face of the circuit 21 and / or to a track 24 of the lower face of said film. circuit 21.
• the holes 33 of the upper film 32 may have the same dimension as the holes 29 of the intermediate film 28, or a greater dimension.
• the holes 29 of the intermediate film 28 may have a dimension equal to, or greater than, that of the holes 25 of the first support 22.
• the invention allows all the possibilities of connections between various tracks of the various conductive networks thus superimposed.
• a track on the lower face of the first circuit 21 can therefore be connected to a track on the " upper face of the film 32, and / or to any other track of the intermediate conducting networks.

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• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Structure Of Printed Boards (AREA)
• Printing Elements For Providing Electric Connections Between Printed Circuits (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9271416

Family Applications (1)

Country Status (4)

Families Citing this family (4)

Family Cites Families (4)

• 1982
  • 1982-02-26 FR FR8203301A patent/FR2522459A1/fr active Granted
• 1983
  • 1983-02-22 EP EP19830900717 patent/EP0101703A1/fr not_active Withdrawn
  • 1983-02-22 JP JP50077083A patent/JPS59500295A/ja active Pending
  • 1983-02-22 WO PCT/FR1983/000031 patent/WO1983003040A1/fr not_active Application Discontinuation

Non-Patent Citations (1)

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